One of the problems facing plug and header-type electrical connectors is providing an adequate, secure connection of the plug to the header. Specifically, there exists a problem of temporary or even permanent electrical disconnection between the plug and the header due to various disturbances (e.g., vibration; motion of equipment; environment; etc.). In particular, most prior art plug and header electrical connector assemblies depend solely on the frictional contact between the electrical connection pins of the header and the plug to provide the securing force for the assembly. However, this minimum securing force provides little, if any, help in combating the effects of the various disturbances mentioned above.
Some prior art plug and header assemblies have tried to address this problem. First, as shown in FIG. 1A, one prior art plug 12 and header 8 assembly utilized a pair of side latching mechanisms 3. These latching mechanisms consisted of two protruding members, or prongs, positioned on either side of the header, which were received by two corresponding receiving areas on the sides of the plug. This assembly, however, provided little help in resolving the problem of disconnection due to vibration or other disturbances. Specifically, when considerable force was placed on the front or back side of the plug, the wire connections moved causing the plug to rock back and forth. This rocking motion caused the receiving areas for the prongs to move relative to the prongs, which in turn increased the possibility that the prongs would slip off the receiving areas causing electrical disconnection.
The prior art also tried utilizing a single latching mechanism 5 to resolve the problem as shown in FIG. 1B. Although this prevented some front to back movement of the plug 12 against the header 8, it did not totally alleviate the problem. By only addressing one side of the connection, the plug is still allowed to move from front to back, relative to the header, and especially at the side opposite the latching mechanism. This movement led eventually to the plug working its way off the pins of the header and eventual disconnection.
Another way to insure a complete and secure connection between the plug and header is to permanently affix the plug to the header after initial connection by using screw-type fasteners or adhesives. However, industry standards require that the plug be removable from the header with a tool. For that reason, adhesives are eliminated from consideration, since they permanently join the plug to the header. Although screw-type fasteners provide a secure connection and also conform the assembly to the industry tool-removal requirement, they add a labor factor and time-consuming constraint. In addition, screw type fasteners increase the material cost for the assembly.
Thus, all of the prior art assemblies that tried to address disconnection problems fail in their attempt to provide a cost-effective, secure, quick and easily removable plug and header assembly for preventing temporary or permanent electrical disconnection.
In addition to the problem of securing the plug to the header, there also exists the problem of misconnecting the electrical members of the header to the appropriate openings in the plug 12, resulting from the misalignment of the plug to the pins of the header when initially connecting the plug to the header. This can occur because the pins of the header and the electrical receiving portions in the plug are equally spaced apart at specified standard distances. A particular pin receiving portion destined for a corresponding pin from the header can easily, and inadvertently, be misplaced onto the wrong pin. The resulting misconnection can lead to a variety of problems such as non-functioning or damaged equipment, damage to the plug and header assembly, and hazardous electrical conditions that can cause shock or fire.
As shown in FIG. 1C, the prior art discloses one solution to this misconnecting problem. FIG. 1C shows the use of a separate "U" shaped pin 7 that is inserted through predrilled holes in the header 8 and also received in a corresponding receiving area on the plug 12 when the plug is properly mated to the header. However, an installer can still mis-align the plug and header initially, only to find out that the assembly is not properly aligned when the installer attempts to install the alignment pin, which will not be received into the plug since it is not properly aligned. In addition to this problem, extra manufacturing costs are encountered since a separate pin must be supplied and installed.